where in turbotax online do I start to calculate and file my estimated taxes for the 2025 tax year?

[xmasbaby0]

The 2025 software will not be available until mid to late November.   Until then, online is only for 2024 returns and does not include the new tax laws that go into effect for 2025.  Not sure what you mean by "file" estimated tax for 2025.  No one will actually file a 2025 tax return until early in 2026.

[baldietax]

do you mean how to pay your estimated tax for 2025 i.e. 1040-ES generally due quarterly, Q3 deadline 9/15 coming up this week?

Turbo doesn't have any role in 'filing' ES during the year, if you're referring to that, you can just pay online at irs.gov if able and make sure to classify it as 1040-ES for 2025.

To calculate how much to pay try some of the online calculators in particular the W4 tool from IRS may be helpful, most tools are not updated yet for 2025 'big bill' changes but it depends whether those changes apply for you.  See also Form 1040-ES instructions which has some worksheets to help with estimation, and Form 2210 lines 1-9 for the safe harbor calculation (i.e. you need to pay during 2025 either thru withholding or "timely" (usually quarterly) estimated tax, the smaller of - 100% of 2024 tax [110% if AGI > 150k or 75k for filing MFS], or 90% of 2025 tax).

If you didn't pay Q1/2 ES but your income was steady and you should have paid those, generally you should pay them right away to stop the penalty accruing, there are other options to reduce the penalty such as increasing withholding the rest of the year (not much time left tho) or try to file Form 2210 Annualized Income method but it may only help if your income is backloaded in later quarters.  It really depends the specifics of your situation.

[VolvoGirl]

To prepare or edit  estimates for next year you start with your current return, but be careful not to change anything.  If you can't get back into your return, Click on Add a State to let you back into your retun.

You can just type W4 in the search box at the top of your return , click on Find. Then Click on Jump To and it will take you to the estimated tax payments section. Say no to changing your W-4 and the next screen will start the estimated taxes section.

Or Go to….

Federal Taxes or Personal (Deskop H&B)

Other Tax Situations

Other Tax Forms

Form W-4 and Estimated Taxes - Click the Start or Update button

In the Desktop program you can switch to Forms and open the Estimated Tax Payments Options sheet.  You can even select to print the estimates with just your personal info and no amounts.  You  can play with and tweak the amounts.  You can open the individual 1040ES forms and override the amounts.  

See,

https://ttlc.intuit.com/community/tax-payments/help/can-turbotax-calculate-next-year-s-federal-estim...

You must make quarterly estimated tax payments for the current tax year if both of the following apply:

- 1. You expect to owe at least $1,000 in tax for the current tax year, after subtracting your withholding and credits.

- 2. You expect your withholding and credits to be less than the smaller of:

    90% of the tax to be shown on your current year’s tax return, or

  100% of the tax shown on your prior year’s tax return. (Your prior year tax return must cover all 12 months).

Individuals whose AGI for the preceding taxable year exceeds $150,000 must pay the lesser of 90% of the tax due for the current year or 110% of the tax on the individual’s return for the prior taxable year

To just estimate the remaining quarters put in that you paid $1 for the missed quarters so it will only calculate the remaining quarters.